This document summarizes several medium access control (MAC) protocols for wireless networks, focusing on those suitable for mobile and energy-efficient operation. It discusses both contention-based protocols like MACA, S-MAC, and B-MAC, which use carrier sensing and random access, as well as schedule-based protocols like LEACH, SMACS, and TRAMA, which establish schedules to avoid collisions. It also covers the IEEE 802.15.4 standard for low-power wireless personal area networks.
The document summarizes key points from an 8th lecture on wireless sensor networks. It discusses various medium access control (MAC) protocols that control when nodes can access a shared wireless medium. These include contention-based protocols like MACA that use RTS/CTS handshaking and schedule-based protocols with fixed or dynamic scheduling. It also describes energy-efficient MAC protocols for low data rate sensor networks like S-MAC, T-MAC, and preamble sampling that increase sleep time to reduce energy use through synchronized sleep schedules or long preambles.
The document summarizes contention-based MAC protocols for wireless sensor networks. It discusses the PAMAS protocol, which provides detailed overhearing avoidance and uses two channels - a data channel and control channel. Signaling packets like RTS, CTS, and busy tones are transmitted on the control channel. It also covers concepts like low duty cycles, wake up mechanisms, and protocols like S-MAC that coordinate node schedules to reduce idle listening. Quizzes are included to test understanding of discussed concepts.
The document discusses MAC layer protocols for wireless networks. It begins by explaining that MAC (Media Access Control) controls access to the shared transmission medium on a local area network. It aims to prevent nodes from interfering with each other's transmissions. Common MAC protocols discussed include CSMA/CD used in Ethernet, and early wireless MAC protocols like MACA which introduced RTS/CTS to avoid the hidden terminal problem. A key part of wireless MAC is the IEEE 802.11 distributed coordination function, which uses carrier sensing, backoff mechanisms and RTS/CTS/DATA/ACK to allow multiple nodes fair access to the shared wireless channel.
This document discusses medium access control (MAC) protocols, which regulate access to a shared wireless medium between nodes. It covers key requirements for MAC protocols including throughput efficiency, fairness, and low overhead. It also describes challenges like the hidden terminal problem, exposed terminal problem, and sources of overhead from collisions, overhearing, and idle listening. Finally, it categorizes common MAC protocols as fixed assignment, demand assignment, and random access and notes additional energy conservation requirements for wireless sensor networks.
The document discusses several MAC protocols for ad hoc networks including MACA, MACAW, and PAMAS. MACA uses RTS and CTS packets to avoid collisions but does not provide ACK. MACAW is a revision of MACA that includes ACK. It significantly increases throughput but does not fully solve hidden and exposed terminal problems. PAMAS uses a separate signaling channel for RTS-CTS and a data channel. It allows nodes to power down transceivers when not transmitting to save energy.
This document discusses various MAC protocols for ad hoc wireless networks. It begins by outlining the key issues in designing such protocols, including bandwidth efficiency, quality of service support, and addressing hidden and exposed terminal problems. It then classifies MAC protocols into contention-based, contention-based with reservation, and contention-based with scheduling categories. Several examples of protocols are described for each category. The document provides an overview of the operation and key aspects of many MAC protocols proposed for ad hoc wireless networks.
The document summarizes key points from an 8th lecture on wireless sensor networks. It discusses various medium access control (MAC) protocols that control when nodes can access a shared wireless medium. These include contention-based protocols like MACA that use RTS/CTS handshaking and schedule-based protocols with fixed or dynamic scheduling. It also describes energy-efficient MAC protocols for low data rate sensor networks like S-MAC, T-MAC, and preamble sampling that increase sleep time to reduce energy use through synchronized sleep schedules or long preambles.
The document summarizes contention-based MAC protocols for wireless sensor networks. It discusses the PAMAS protocol, which provides detailed overhearing avoidance and uses two channels - a data channel and control channel. Signaling packets like RTS, CTS, and busy tones are transmitted on the control channel. It also covers concepts like low duty cycles, wake up mechanisms, and protocols like S-MAC that coordinate node schedules to reduce idle listening. Quizzes are included to test understanding of discussed concepts.
The document discusses MAC layer protocols for wireless networks. It begins by explaining that MAC (Media Access Control) controls access to the shared transmission medium on a local area network. It aims to prevent nodes from interfering with each other's transmissions. Common MAC protocols discussed include CSMA/CD used in Ethernet, and early wireless MAC protocols like MACA which introduced RTS/CTS to avoid the hidden terminal problem. A key part of wireless MAC is the IEEE 802.11 distributed coordination function, which uses carrier sensing, backoff mechanisms and RTS/CTS/DATA/ACK to allow multiple nodes fair access to the shared wireless channel.
This document discusses medium access control (MAC) protocols, which regulate access to a shared wireless medium between nodes. It covers key requirements for MAC protocols including throughput efficiency, fairness, and low overhead. It also describes challenges like the hidden terminal problem, exposed terminal problem, and sources of overhead from collisions, overhearing, and idle listening. Finally, it categorizes common MAC protocols as fixed assignment, demand assignment, and random access and notes additional energy conservation requirements for wireless sensor networks.
The document discusses several MAC protocols for ad hoc networks including MACA, MACAW, and PAMAS. MACA uses RTS and CTS packets to avoid collisions but does not provide ACK. MACAW is a revision of MACA that includes ACK. It significantly increases throughput but does not fully solve hidden and exposed terminal problems. PAMAS uses a separate signaling channel for RTS-CTS and a data channel. It allows nodes to power down transceivers when not transmitting to save energy.
This document discusses various MAC protocols for ad hoc wireless networks. It begins by outlining the key issues in designing such protocols, including bandwidth efficiency, quality of service support, and addressing hidden and exposed terminal problems. It then classifies MAC protocols into contention-based, contention-based with reservation, and contention-based with scheduling categories. Several examples of protocols are described for each category. The document provides an overview of the operation and key aspects of many MAC protocols proposed for ad hoc wireless networks.
This document discusses various MAC protocols for ad hoc wireless networks. It begins by outlining key issues in designing MAC protocols for these networks, such as bandwidth efficiency, quality of service support, and the hidden and exposed terminal problems. It then covers classifications of MAC protocols including contention-based, contention-based with reservation mechanisms, and contention-based with scheduling mechanisms. Specific protocols are discussed within each category.
The document summarizes MAC protocols for wireless mesh networks. It begins with an introduction to wireless mesh network architectures and important definitions. It then discusses single channel MAC protocols like S-MAC, T-MAC, and a new TDMA-based protocol. It also covers multi-channel MAC protocols classifications and examples like CC-MMAC and SSCH MAC. The document provides detailed explanations of the mechanisms and concepts behind various single and multi-channel MAC protocols.
Mac protocols for ad hoc wireless networks Divya Tiwari
The document discusses MAC protocols for ad hoc wireless networks. It addresses key issues in designing MAC protocols including limited bandwidth, quality of service support, synchronization, hidden and exposed terminal problems, error-prone shared channels, distributed coordination without centralized control, and node mobility. Common MAC protocol classifications and examples are also presented, such as contention-based protocols, sender-initiated versus receiver-initiated protocols, and protocols using techniques like reservation, scheduling, and directional antennas.
This slides about Wireless sensor network MAC protocol,
There are bunch of MAC protocol in research field.
It classify the MAC protocol and summarize the feature of typical sensor network MAC protcol
Mac protocols sensor_20071105_slideshareChih-Yu Lin
This document summarizes several MAC protocols for wireless sensor networks. It begins by introducing the need for MAC protocols to control medium access in wireless networks and common sources of energy waste. It then categorizes MAC protocols as contention-based (like ALOHA and CSMA), schedule-based (like TDMA), or hybrid. Specific protocols discussed include S-MAC, B-MAC, TRAMA, and hybrid protocols like Z-MAC and Funneling-MAC. The document emphasizes energy efficiency as the primary concern for MAC protocols in wireless sensor networks.
The document discusses medium access control (MAC) protocols for wireless ad-hoc networks. It describes several MAC protocols including the Five Phase Reservation Protocol (FPRP) and Distributed Wireless Ordering Protocol (DWOP). FPRP uses a five phase process for distributed reservation of time slots. DWOP aims to provide fair channel access that approximates a first-in-first-out scheduling order by sharing packet arrival times between nodes. The document evaluates these protocols and discusses their advantages in providing quality of service guarantees and fair scheduling in wireless ad-hoc networks.
Wireless Sensors Networks - MAC protocols - TDMAShehla Shoaib
1) The document discusses the TDMA protocol for wireless sensor networks.
2) TDMA divides time into slots and allows only one sensor to transmit per slot, preventing collisions.
3) It saves power by allowing sensors to turn off their radios except during their allocated time slot.
An energy efficient mac protocol for wirelessnabil_alsharafi
This document presents S-MAC, an energy-efficient MAC protocol designed for wireless sensor networks. S-MAC aims to reduce energy consumption through the use of synchronized duty cycles where nodes periodically listen and sleep. It also supports self-configuration. The paper describes the characteristics of WSNs that require a different MAC approach than IEEE 802.11. Experiments show that S-MAC achieves significant energy savings of around 98% compared to IEEE 802.11 through the use of duty cycles and avoiding overhearing. However, S-MAC can introduce increased latency and may not perform as well as other protocols under heavy traffic loads. Tradeoffs between energy consumption and latency can be tuned by adjusting the duty cycle parameters.
The document discusses several IEEE 802 standards for local and metropolitan area networks. It describes the purpose of IEEE 802 standards to define physical network interfaces and the lowest three layers of the network architecture. It provides details on some famous IEEE 802 standards including 802.2 (LLC), 802.3 (Ethernet), 802.4 (Token Bus), 802.5 (Token Ring), 802.6 (DQDB), and 802.11 (Wireless LAN). It then focuses on explaining the Ethernet, Token Bus and Token Ring standards in more depth including their frame formats and other specifications.
This document summarizes a tutorial on mobile ad hoc networks. It first discusses the characteristics and challenges of mobile ad hoc networks, including frequent topology changes and limited bandwidth. It then covers various aspects of designing protocols for mobile ad hoc networks, including medium access control, routing, and transport. For medium access control, it describes MACA and IEEE 802.11. For routing, it discusses reactive, proactive, and hybrid routing protocols and the tradeoffs between them. The document provides an overview of key considerations and approaches for building mobile ad hoc network protocols.
The document summarizes mobile ad hoc networks (MANETs) and some of the key challenges in designing protocols for them. It covers medium access control protocols, routing protocols, and some examples. Specifically, it discusses MACA for medium access, reactive routing protocols like DSR, proactive protocols like DSDV, and hybrid protocols like ZRP. It also outlines some of the tradeoffs between proactive and reactive routing approaches for mobile networks.
Lecture 19 22. transport protocol for ad-hoc Chandra Meena
This document discusses transport layer protocols for mobile ad hoc networks (MANETs). It begins with an introduction to MANETs and the need for new network architectures and protocols to support new types of networks. It then provides an overview of TCP/IP and how TCP works, including congestion control mechanisms. The document discusses challenges for TCP over wireless networks, where packet losses are often due to errors rather than congestion. It covers different versions of TCP and their approaches to congestion control. The goal is to design transport layer protocols that can address the unreliable links and frequent topology changes in MANETs.
The document discusses MAC protocols for ad hoc networks. It begins by outlining problems MAC protocols must address, such as bandwidth efficiency, synchronization, and the hidden terminal problem. It then classifies MAC protocols into three categories: contention-based without reservation, contention-based with reservation, and contention-based with scheduling. Several example protocols are described for each category, including how they address issues like bandwidth utilization and collisions. The document also covers MAC protocols that use directional antennas and power control techniques.
Lecture 7 8 ad hoc wireless media access protocolsChandra Meena
1) The document discusses issues with media access control (MAC) protocols in ad hoc wireless networks, including problems like hidden terminals and exposed nodes.
2) It classifies MAC protocols as synchronous, asynchronous, receiver-initiated, or sender-initiated. The RTS-CTS handshake is presented as a solution to the hidden terminal problem.
3) However, the RTS-CTS approach has shortcomings like collisions when RTS and CTS messages are sent by different nodes or when multiple CTS messages are granted. Solutions to the exposed node problem are also discussed.
This is the bottom sublayer of the Data Link Layer. This Chapter is especially relevant for LANs.
4.1 The Channel Allocation Problem
How to allocate a single channel among multiple users.
4.2 Multiple Access Protocols
How to handle contention for the use of a channel.
4.3 IEEE Standards for LANs
How do the protocols of the last sections apply to real systems. Here we talk about the actual standards in use.
4.4 Bridges
Ways of connecting networks together.
4.5 High Speed LANs
Directions in high speed networks.
El documento describe las tecnologías xDSL, incluyendo ADSL, SDSL, HDSL y VDSL. Explica que xDSL permite el acceso de banda ancha a Internet a través de las líneas telefónicas existentes. Las diferentes tecnologías xDSL varían en velocidad, distancia máxima y si son asimétricas o simétricas. El documento también describe los equipos como DSLAM, modem y router necesarios para implementar una red xDSL.
The document discusses the Medium Access Control (MAC) sublayer of the data link layer and various protocols for determining which device can access a shared communication channel. It focuses on static and dynamic channel allocation problems in local area networks (LANs) and wireless networks. Static allocation wastes bandwidth by assigning each user a fixed portion of the channel even when they are not transmitting. Dynamic protocols like ALOHA and carrier sense multiple access (CSMA) aim to improve channel utilization by allowing users to transmit only when the channel is idle.
LAN es una red de área local que conecta computadoras, impresoras y otros dispositivos electrónicos dentro de un edificio o campus. Proporciona ventajas como compartir recursos e información de forma rápida y económica, pero también puede presentar desventajas como limitaciones de alcance y problemas de seguridad.
This document discusses various MAC protocols for ad hoc wireless networks. It begins by outlining key issues in designing MAC protocols for these networks, such as bandwidth efficiency, quality of service support, and the hidden and exposed terminal problems. It then covers classifications of MAC protocols including contention-based, contention-based with reservation mechanisms, and contention-based with scheduling mechanisms. Specific protocols are discussed within each category.
The document summarizes MAC protocols for wireless mesh networks. It begins with an introduction to wireless mesh network architectures and important definitions. It then discusses single channel MAC protocols like S-MAC, T-MAC, and a new TDMA-based protocol. It also covers multi-channel MAC protocols classifications and examples like CC-MMAC and SSCH MAC. The document provides detailed explanations of the mechanisms and concepts behind various single and multi-channel MAC protocols.
Mac protocols for ad hoc wireless networks Divya Tiwari
The document discusses MAC protocols for ad hoc wireless networks. It addresses key issues in designing MAC protocols including limited bandwidth, quality of service support, synchronization, hidden and exposed terminal problems, error-prone shared channels, distributed coordination without centralized control, and node mobility. Common MAC protocol classifications and examples are also presented, such as contention-based protocols, sender-initiated versus receiver-initiated protocols, and protocols using techniques like reservation, scheduling, and directional antennas.
This slides about Wireless sensor network MAC protocol,
There are bunch of MAC protocol in research field.
It classify the MAC protocol and summarize the feature of typical sensor network MAC protcol
Mac protocols sensor_20071105_slideshareChih-Yu Lin
This document summarizes several MAC protocols for wireless sensor networks. It begins by introducing the need for MAC protocols to control medium access in wireless networks and common sources of energy waste. It then categorizes MAC protocols as contention-based (like ALOHA and CSMA), schedule-based (like TDMA), or hybrid. Specific protocols discussed include S-MAC, B-MAC, TRAMA, and hybrid protocols like Z-MAC and Funneling-MAC. The document emphasizes energy efficiency as the primary concern for MAC protocols in wireless sensor networks.
The document discusses medium access control (MAC) protocols for wireless ad-hoc networks. It describes several MAC protocols including the Five Phase Reservation Protocol (FPRP) and Distributed Wireless Ordering Protocol (DWOP). FPRP uses a five phase process for distributed reservation of time slots. DWOP aims to provide fair channel access that approximates a first-in-first-out scheduling order by sharing packet arrival times between nodes. The document evaluates these protocols and discusses their advantages in providing quality of service guarantees and fair scheduling in wireless ad-hoc networks.
Wireless Sensors Networks - MAC protocols - TDMAShehla Shoaib
1) The document discusses the TDMA protocol for wireless sensor networks.
2) TDMA divides time into slots and allows only one sensor to transmit per slot, preventing collisions.
3) It saves power by allowing sensors to turn off their radios except during their allocated time slot.
An energy efficient mac protocol for wirelessnabil_alsharafi
This document presents S-MAC, an energy-efficient MAC protocol designed for wireless sensor networks. S-MAC aims to reduce energy consumption through the use of synchronized duty cycles where nodes periodically listen and sleep. It also supports self-configuration. The paper describes the characteristics of WSNs that require a different MAC approach than IEEE 802.11. Experiments show that S-MAC achieves significant energy savings of around 98% compared to IEEE 802.11 through the use of duty cycles and avoiding overhearing. However, S-MAC can introduce increased latency and may not perform as well as other protocols under heavy traffic loads. Tradeoffs between energy consumption and latency can be tuned by adjusting the duty cycle parameters.
The document discusses several IEEE 802 standards for local and metropolitan area networks. It describes the purpose of IEEE 802 standards to define physical network interfaces and the lowest three layers of the network architecture. It provides details on some famous IEEE 802 standards including 802.2 (LLC), 802.3 (Ethernet), 802.4 (Token Bus), 802.5 (Token Ring), 802.6 (DQDB), and 802.11 (Wireless LAN). It then focuses on explaining the Ethernet, Token Bus and Token Ring standards in more depth including their frame formats and other specifications.
This document summarizes a tutorial on mobile ad hoc networks. It first discusses the characteristics and challenges of mobile ad hoc networks, including frequent topology changes and limited bandwidth. It then covers various aspects of designing protocols for mobile ad hoc networks, including medium access control, routing, and transport. For medium access control, it describes MACA and IEEE 802.11. For routing, it discusses reactive, proactive, and hybrid routing protocols and the tradeoffs between them. The document provides an overview of key considerations and approaches for building mobile ad hoc network protocols.
The document summarizes mobile ad hoc networks (MANETs) and some of the key challenges in designing protocols for them. It covers medium access control protocols, routing protocols, and some examples. Specifically, it discusses MACA for medium access, reactive routing protocols like DSR, proactive protocols like DSDV, and hybrid protocols like ZRP. It also outlines some of the tradeoffs between proactive and reactive routing approaches for mobile networks.
Lecture 19 22. transport protocol for ad-hoc Chandra Meena
This document discusses transport layer protocols for mobile ad hoc networks (MANETs). It begins with an introduction to MANETs and the need for new network architectures and protocols to support new types of networks. It then provides an overview of TCP/IP and how TCP works, including congestion control mechanisms. The document discusses challenges for TCP over wireless networks, where packet losses are often due to errors rather than congestion. It covers different versions of TCP and their approaches to congestion control. The goal is to design transport layer protocols that can address the unreliable links and frequent topology changes in MANETs.
The document discusses MAC protocols for ad hoc networks. It begins by outlining problems MAC protocols must address, such as bandwidth efficiency, synchronization, and the hidden terminal problem. It then classifies MAC protocols into three categories: contention-based without reservation, contention-based with reservation, and contention-based with scheduling. Several example protocols are described for each category, including how they address issues like bandwidth utilization and collisions. The document also covers MAC protocols that use directional antennas and power control techniques.
Lecture 7 8 ad hoc wireless media access protocolsChandra Meena
1) The document discusses issues with media access control (MAC) protocols in ad hoc wireless networks, including problems like hidden terminals and exposed nodes.
2) It classifies MAC protocols as synchronous, asynchronous, receiver-initiated, or sender-initiated. The RTS-CTS handshake is presented as a solution to the hidden terminal problem.
3) However, the RTS-CTS approach has shortcomings like collisions when RTS and CTS messages are sent by different nodes or when multiple CTS messages are granted. Solutions to the exposed node problem are also discussed.
This is the bottom sublayer of the Data Link Layer. This Chapter is especially relevant for LANs.
4.1 The Channel Allocation Problem
How to allocate a single channel among multiple users.
4.2 Multiple Access Protocols
How to handle contention for the use of a channel.
4.3 IEEE Standards for LANs
How do the protocols of the last sections apply to real systems. Here we talk about the actual standards in use.
4.4 Bridges
Ways of connecting networks together.
4.5 High Speed LANs
Directions in high speed networks.
El documento describe las tecnologías xDSL, incluyendo ADSL, SDSL, HDSL y VDSL. Explica que xDSL permite el acceso de banda ancha a Internet a través de las líneas telefónicas existentes. Las diferentes tecnologías xDSL varían en velocidad, distancia máxima y si son asimétricas o simétricas. El documento también describe los equipos como DSLAM, modem y router necesarios para implementar una red xDSL.
The document discusses the Medium Access Control (MAC) sublayer of the data link layer and various protocols for determining which device can access a shared communication channel. It focuses on static and dynamic channel allocation problems in local area networks (LANs) and wireless networks. Static allocation wastes bandwidth by assigning each user a fixed portion of the channel even when they are not transmitting. Dynamic protocols like ALOHA and carrier sense multiple access (CSMA) aim to improve channel utilization by allowing users to transmit only when the channel is idle.
LAN es una red de área local que conecta computadoras, impresoras y otros dispositivos electrónicos dentro de un edificio o campus. Proporciona ventajas como compartir recursos e información de forma rápida y económica, pero también puede presentar desventajas como limitaciones de alcance y problemas de seguridad.
The document discusses local area networks (LANs). It defines a LAN as a network that interconnects data communication devices within a small geographic area and broadcasts data at high transfer rates. Examples of connected devices include PCs, workstations, and printers. Common LAN topologies discussed include bus, star, ring, and wireless configurations. The document also covers the roles and components of TCP/IP networking layers.
Fast Ethernet increased the bandwidth of standard Ethernet from 10 Mbps to 100 Mbps. It used the same CSMA/CD access method and frame format as standard Ethernet but with some changes to address the higher speed. Fast Ethernet was implemented over twisted pair cables using 100BASE-TX or over fiber optic cables using 100BASE-FX. The increased speed enabled Fast Ethernet to compete with other high-speed LAN technologies of the time like FDDI.
Medium access control (MAC) is the sublayer of the data link layer that coordinates use of a shared medium in wireless networks. It addresses problems like hidden and exposed terminals through techniques like carrier sense multiple access (CSMA) and time division multiple access (TDMA). TDMA divides time into slots and assigns slots to different users to avoid collisions. Early random access protocols like Aloha and slotted Aloha had low throughput due to many collisions, while later protocols use RTS/CTS handshaking and carrier sensing to reduce collisions and improve throughput.
A network allows two or more electronic devices to connect and exchange data. Computers can be connected via cables, wireless connections, phone lines, or satellite links. Networks allow users to share files and resources, communicate, store data centrally, and access the internet for services, information, and entertainment. Special server computers provide centralized services to other computers on the network like file storage, printing, and user access control. Common network topologies include bus, ring, star, and hybrid configurations. Wireless networks use radio signals instead of cables. Network hardware like network interface cards, cables, hubs, switches, routers, firewalls, proxies, bridges, and modems facilitate device connections and data exchange within networks.
Medium Access PROTOCOL b yENGR. FAWAD KHAN UET BANNU KP PAKISTANirfan sami
1. The document discusses medium access control (MAC) protocols for shared broadcast links at the link layer. It covers three main classes of MAC protocols: channel partitioning, random access, and "taking turns" protocols.
2. Channel partitioning protocols like TDMA and FDMA divide the channel into time or frequency slots and allocate slots to nodes. Random access protocols like ALOHA, CSMA, and CSMA/CD allow nodes to transmit randomly and include mechanisms to detect and handle collisions. "Taking turns" protocols such as polling and token passing coordinate channel access by having nodes take turns transmitting.
3. The ideal MAC protocol allows single or multiple nodes to transmit at the maximum channel rate, is fully decentralized, requires
The document discusses various medium access control protocols for local area networks:
1. Static channel allocation protocols like Frequency-Division Multiplexing (FDM) can waste bandwidth if the number of users is not exactly equal to the number of allocated channels.
2. Dynamic channel allocation protocols do not pre-allocate channels. The ALOHA and CSMA protocols allow nodes to transmit whenever the channel is sensed to be idle, which can still result in collisions.
3. Slotted ALOHA improves on pure ALOHA by only allowing transmissions to start at discrete time slots, doubling its maximum throughput. Carrier sensing in CSMA helps reduce but does not eliminate the possibility of collisions.
This document discusses three types of computer networks: local area networks (LANs), metropolitan area networks (MANs), and wide area networks (WANs). LANs connect computers within a limited local area like a home or single building. MANs operate within a larger area like a city using technologies like fiber cables and satellites. WANs cover the largest geographic areas, even spanning countries or borders, using long-distance transmission media.
This document provides an overview of local area networks (LANs) and their components. It discusses the different types of computer networks and LAN topologies. It also describes some key LAN devices like hubs, switches, routers, wireless access points, and network interface cards. It provides an introduction to the TCP/IP networking protocols and the IEEE 802.11 wireless networking standards.
This document discusses different medium access control protocols. It covers random access protocols like ALOHA and slotted ALOHA, carrier sensing protocols like CSMA and CSMA/CD, and scheduling protocols like polling and token passing. It provides analysis of the throughput and efficiency of these different MAC protocols. It also compares the approaches and discusses factors in selecting a MAC protocol.
This document discusses different types of networking devices used to connect local area networks (LANs). It describes hubs, repeaters, bridges, routers, and gateways. Hubs and repeaters operate at the physical layer, bridges operate at the physical and data link layers, and routers and gateways operate at the network layer and above to connect multiple networks and perform protocol conversion. The document provides details on the functions and characteristics of each type of device.
This document provides an overview of key concepts in computer networks and communication. It defines what a network is, discusses the need for networking and sharing of resources, and outlines the evolution of early networks like ARPANET and NSFNET into the modern Internet. It also covers network topologies, transmission media, switching techniques, common network devices, and communication protocols.
This document discusses MAC protocols for ad hoc wireless networks. It begins by outlining key issues in designing MAC protocols, such as bandwidth efficiency, quality of service support, and addressing hidden and exposed terminal problems. It then classifies MAC protocols into contention-based, contention-based with reservation mechanisms, and contention-based with scheduling mechanisms. Several example protocols are described for each category, including how they address the issues outlined earlier in the document.
This document discusses various MAC protocols for ad hoc wireless networks. It begins by outlining key issues in designing MAC protocols for these networks, such as bandwidth efficiency, quality of service support, and the hidden and exposed terminal problems. It then covers classifications of MAC protocols including contention-based, contention-based with reservation mechanisms, and contention-based with scheduling mechanisms. Specific protocols are discussed within each category.
This document discusses MAC protocols for ad-hoc wireless networks. It begins by outlining key issues in designing these protocols, such as bandwidth efficiency, quality of service support, and the hidden/exposed terminal problems. It then describes the classifications of MAC protocols, including contention-based, contention-based with reservation, and contention-based with scheduling mechanisms. Several example protocols are discussed for each classification, including how they address the issues and provide distributed channel access in ad-hoc networks.
This document summarizes several MAC layer protocols for sensor networks: S-MAC, T-MAC, B-MAC, and P-MAC. S-MAC trades throughput and latency for energy efficiency by having nodes periodically sleep. T-MAC further improves energy savings by transmitting messages in variable length bursts and sleeping between. B-MAC focuses on low power operation, collision avoidance, and scalability through clear channel assessment and preamble sampling. P-MAC uses patterns of 0s and 1s to schedule transmissions and receptions to trade off latency and energy usage. The document concludes that B-MAC generally performs best but its interface could be simplified through a middleware service.
This document provides a summary of a lecture on the data link layer. It discusses how shared broadcast mediums require protocols for nodes to share the channel to avoid collisions. It introduces the CSMA/CD protocol used in early Ethernet networks, which uses carrier sensing and collision detection to allow multiple nodes to transmit over a shared broadcast medium in a distributed manner. It also discusses limitations of CSMA/CD and how modern Ethernet networks evolved to use switching to create point-to-point links between nodes rather than a shared broadcast medium.
The document discusses the data link layer. It covers the following key points in 3 sentences:
The data link layer provides services such as error detection, multiple access control for shared mediums, and link layer addressing. It discusses various techniques for error detection and correction as well as multiple access protocols including CSMA/CD, TDMA, and ALOHA. The data link layer is implemented in network interface cards in each host and is responsible for framing data, performing error checking, and transferring frames between adjacent nodes over a link.
The document discusses MAC protocols for wireless sensor networks. It begins by outlining issues in designing MAC protocols for ad-hoc wireless networks, such as bandwidth efficiency, quality of service support, synchronization, and the error-prone shared wireless medium. It then describes the design goals of MAC protocols. The document classifies MAC protocols into three categories: contention-based protocols, contention-based protocols with reservation mechanisms, and contention-based protocols with scheduling mechanisms. Several examples are provided for each category, including MACA, FAMA, and RTMAC protocols.
The document outlines an algorithmic foundations of ad hoc networks tutorial, including:
1) An introduction and thanks to the organizers.
2) An agenda covering topics like routing, medium access control, power control, and sensor network protocols.
3) A discussion of medium access control protocols for wireless networks like CSMA, Aloha, Ethernet, and IEEE 802.11, focusing on techniques for avoiding collisions in distributed environments.
The document discusses MAC protocols for ad hoc networks. It begins by outlining problems MAC protocols must address, such as bandwidth efficiency, hidden/exposed terminals, and mobility. It then classifies MAC protocols into contention-based without reservation, contention-based with reservation, and contention-based with scheduling. Examples are provided for each category, including MACA, BTMA, D-PRMA, and DPS. The document also covers MAC protocols that use directional antennas to improve throughput and reuse.
This document discusses various contention-based MAC protocols for ad-hoc and sensor networks. It describes the protocols MACA, MACAW, MACA-BI, BTMA, DBTMA, and RI-BTMA. These protocols differ in how they handle issues like hidden and exposed terminals and whether they are sender-initiated or receiver-initiated. A table compares the protocols based on how well they solve hidden/exposed terminal problems, their throughput, fairness, the signals they use, whether they use a single or multiple channel, and whether they are sender-initiated or receiver-initiated.
MAC PROTOCOLS FOR AD HOC WIRELESS NETWORKS
Issues in designing a MAC Protocol- Classification of MAC Protocols- Contention based protocols- Contention based protocols with Reservation Mechanisms- Contention based protocols with Scheduling Mechanisms – Multi channel MAC-IEEE 802.11
The document discusses computer networks and media access control. It covers topics like Ethernet, wireless LANs, Bluetooth, Wi-Fi, switching, bridging, IP, and more. The key points are:
1. It provides an overview of the topics to be discussed, including media access control, Ethernet standards, wireless technologies, and internetworking basics.
2. It summarizes the evolution of Ethernet and discusses its physical properties, frame format, addressing, and transmitter algorithm using CSMA/CD.
3. It describes wireless LAN standards like Bluetooth and Wi-Fi, addressing problems in wireless networks, and discussing concepts like spread spectrum, CSMA/CA, and network architectures.
This document discusses MAC protocols for wireless sensor networks. It begins by explaining the role and classifications of MAC protocols, and then discusses specific considerations for WSNs, including balancing requirements, energy problems at the MAC layer, and the need for low complexity. It covers low duty cycle protocols that use periodic sleep and wakeup cycles to reduce energy consumption from idle listening. Specific protocols mentioned include S-MAC, the mediation device protocol, and wakeup concepts using cycled receivers and periodic wakeup schemes.
This document summarizes key concepts from a lecture on physical and link layer networking. It discusses how digital signals are encoded and transmitted over analog physical media using modulation techniques. It also covers how bits are organized into packets using framing, techniques for error detection and recovery, and different methods for sharing a communication channel using multiple access protocols like TDMA, FDMA, and random access protocols. The document provides an overview of these fundamental networking concepts in under 15 pages.
The document discusses various medium access control (MAC) protocols used for determining which device should access a shared communication channel. It covers multiple access protocols including ALOHA, slotted ALOHA, carrier sense multiple access (CSMA), CSMA with collision detection, and collision-free protocols like bit-map and binary countdown. It also discusses limited-contention protocols, the adaptive tree walk protocol, wavelength division multiple access, wireless LAN protocols like MACA and MACAW, and Ethernet.
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Thesis Presentation on Renewal theory based 802.15.6 latest.pptxssuserc02c1f
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Medium Access Control (MAC) protocols provide reliable communication between nodes sharing the same physical medium. For wireless networks, MAC protocols must address power efficiency and scalability challenges. Common MAC approaches include random access protocols like CSMA/CA, scheduled access using TDMA, and hybrid approaches. Duty-cycling techniques like low power listening in B-MAC aim to minimize idle listening to reduce energy use.
The document discusses the medium access control sub layer and various protocols used for channel allocation in computer networks, including ALOHA, carrier sense multiple access, collision-free protocols, and Ethernet. It describes how these protocols handle situations where multiple devices attempt to access shared network resources simultaneously to avoid collisions. Key aspects covered include how the protocols determine which device gets to use the channel, detect collisions, and retransmit frames when collisions occur to maximize throughput.
6590 Research Paper Review: MAC Protocol for Multi-Hop Multicast in Adhoc Net...Osama Askoura
This document proposes a new MAC protocol for reliable multicast over multi-hop wireless ad hoc networks. The protocol introduces RTS/CTS to the multicast MAC protocol to solve problems like hidden terminals. It works by having members send concurrent CTS messages on orthogonal frequencies in response to RTS. Performance analysis shows it achieves higher throughput and goodput than prior protocols like ABM, MMP, LBP, by reducing dropped packets and failures while keeping overhead low.
2. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols2
Goals of this chapter
• Controlling when to send a packet and when to listen for a
packet are perhaps the two most important operations in a
wireless network
• Especially, idly waiting wastes huge amounts of energy
• This chapter discusses schemes for this medium access
control that are
• Suitable to mobile and wireless networks
• Emphasize energy-efficient operation
3. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols3
Overview
• Principal options and difficulties
• Contention-based protocols
• Schedule-based protocols
• IEEE 802.15.4
4. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols4
Principal options and difficulties
• Medium access in wireless networks is difficult mainly
because of
• Impossible (or very difficult) to sende and receive at the same time
• Interference situation at receiver is what counts for transmission
success, but can be very different from what sender can observe
• High error rates (for signaling packets) compound the issues
• Requirement
• As usual: high throughput, low overhead, low error rates, …
• Additionally: energy-efficient, handle switched off devices!
5. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols5
Requirements for energy-efficient MAC protocols
• Recall
• Transmissions are costly
• Receiving about as expensive as transmitting
• Idling can be cheaper but is still expensive
• Energy problems
• Collisions – wasted effort when two packets collide
• Overhearing – waste effort in receiving a packet destined for
another node
• Idle listening – sitting idly and trying to receive when nobody is
sending
• Protocol overhead
• Always nice: Low complexity solution
6. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols6
Main options
Wireless medium access
Centralized
Distributed
Contention-
based
Schedule-
based
Fixed
assignment
Demand
assignment
Contention-
based
Schedule-
based
Fixed
assignment
Demand
assignment
7. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols7
Centralized medium access
• Idea: Have a central station control when a node may
access the medium
• Example: Polling, centralized computation of TDMA schedules
• Advantage: Simple, quite efficient (e.g., no collisions), burdens the
central station
• Not directly feasible for non-trivial wireless network sizes
• But: Can be quite useful when network is somehow divided
into smaller groups
• Clusters, in each cluster medium access can be controlled
centrally – compare Bluetooth piconets, for example
! Usually, distributed medium access is considered
8. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols8
Schedule- vs. contention-based MACs
• Schedule-based MAC
• A schedule exists, regulating which participant may use which resource at
which time (TDMA component)
• Typical resource: frequency band in a given physical space (with a given
code, CDMA)
• Schedule can be fixed or computed on demand
• Usually: mixed – difference fixed/on demand is one of time scales
• Usually, collisions, overhearing, idle listening no issues
• Needed: time synchronization!
• Contention-based protocols
• Risk of colliding packets is deliberately taken
• Hope: coordination overhead can be saved, resulting in overall improved
efficiency
• Mechanisms to handle/reduce probability/impact of collisions required
• Usually, randomization used somehow
9. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols9
Overview
• Principal options and difficulties
• Contention-based protocols
• MACA
• S-MAC, T-MAC
• Preamble sampling, B-MAC
• PAMAS
• Schedule-based protocols
• IEEE 802.15.4
10. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols10
A
Distributed, contention-based MAC
• Basic ideas for a distributed MAC
• ALOHA – no good in most cases
• Listen before talk (Carrier Sense Multiple Access, CSMA) –
better, but suffers from sender not knowing what is going on at
receiver, might destroy packets despite first listening for a
! Receiver additionally needs some possibility to inform
possible senders in its vicinity about impending
transmission (to “shut them up” for this duration)
B C D
Hidden
terminal
scenario:
Also:
recall
exposed
terminal
scenario
11. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols11
Main options to shut up senders
• Receiver informs potential interferers while a reception is
on-going
• By sending out a signal indicating just that
• Problem: Cannot use same channel on which actual reception
takes place
! Use separate channel for signaling
• Busy tone protocol
• Receiver informs potential interferers before a reception
is on-going
• Can use same channel
• Receiver itself needs to be informed, by sender, about impending
transmission
• Potential interferers need to be aware of such information, need
to store it
12. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols12
Receiver informs interferers before transmission – MACA
• Sender B asks receiver C
whether C is able to receive a
transmission
Request to Send (RTS)
• Receiver C agrees, sends out
a Clear to Send (CTS)
• Potential interferers overhear
either RTS or CTS and know
about impending transmission
and for how long it will last
• Store this information in a
Network Allocation Vector
• B sends, C acks
! MACA protocol (used e.g. in
IEEE 802.11)
13. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols13
RTS/CTS
• RTS/CTS ameliorate, but do not solve hidden/exposed
terminal problems
• Example problem cases:
14. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols14
MACA Problem: Idle listening
• Need to sense carrier for RTS or CTS packets
• In some form shared by many CSMA variants; but e.g. not by busy
tones
• Simple sleeping will break the protocol
• IEEE 802.11 solution: ATIM windows & sleeping
• Basic idea: Nodes that have data buffered for receivers send
traffic indicators at pre-arranged points in time
• Receivers need to wake up at these points, but can sleep
otherwise
• Parameters to adjust in MACA
• Random delays – how long to wait between listen/transmission
attempts?
• Number of RTS/CTS/ACK re-trials?
• …
15. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols15
Sensor-MAC (S-MAC)
• MACA’s idle listening is particularly unsuitable if average data rate is
low
• Most of the time, nothing happens
• Idea: Switch nodes off, ensure that neighboring nodes turn on
simultaneously to allow packet exchange (rendez-vous)
• Only in these active periods,
packet exchanges happen
• Need to also exchange
wakeup schedule between
neighbors
• When awake, essentially
perform RTS/CTS
• Use SYNCH, RTS, CTS
phases
16. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols16
S-MAC synchronized islands
• Nodes try to pick up schedule synchronization from
neighboring nodes
• If no neighbor found, nodes pick some schedule to start
with
• If additional nodes join, some node might learn about two
different schedules from different nodes
• “Synchronized islands”
• To bridge this gap, it has to follow both schemes
Time
A A A A
C C C C
A
B B B B
D D D
A
C
B
D
E E E EE E E
17. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols17
Timeout-MAC (T-MAC)
• In S-MAC, active period is of
constant length
• What if no traffic actually
happens?
• Nodes stay awake needlessly
long
• Idea: Prematurely go back to
sleep mode when no traffic has
happened for a certain time
(=timeout) ! T-MAC
• Adaptive duty cycle!
• One ensuing problem: Early
sleeping
• C wants to send to D, but is
hindered by transmission A! B
• Two solutions exist – homework!
A B C D
RTS
CTS
DATA
May not
send
Timeout,
go back to
sleep as
nothing
happened
ACK
RTS
18. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols18
Preamble Sampling
• So far: Periodic sleeping supported by some means to
synchronize wake up of nodes to ensure rendez-vous
between sender and receiver
• Alternative option: Don’t try to explicitly synchronize nodes
• Have receiver sleep and only periodically sample the channel
• Use long preambles to ensure that receiver stays awake
to catch actual packet
• Example: WiseMAC
Check
channel
Check
channel
Check
channel
Check
channel
Start transmission:
Long preamble Actual packet
Stay awake!
19. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols19
B-MAC
• Combines several of the above discussed ideas
• Takes care to provide practically relevant solutions
• Clear Channel Assessment
• Adapts to noise floor by sampling channel when it is assumed to
be free
• Samples are exponentially averaged, result used in gain control
• For actual assessment when sending a packet, look at five
channel samples – channel is free if even a single one of them is
significantly below noise
• Optional: random backoff if channel is found busy
• Optional: Immediate link layer acknowledgements for
received packets
20. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols20
B-MAC II
• Low Power Listening (= preamble sampling)
• Uses the clear channel assessment techniques to decide whether
there is a packet arriving when node wakes up
• Timeout puts node back to sleep if no packet arrived
• B-MAC does not have
• Synchronization
• RTS/CTS
• Results in simpler, leaner implementation
• Clean and simple interface
• Currently: Often considered as the default WSN MAC
protocol
21. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols21
Power Aware Multiaccess with Signaling – PAMAS
• Idea: combine busy tone with RTS/CTS
• Results in detailed overhearing avoidance, does not address idle
listening
• Uses separate data and control channels
• Procedure
• Node A transmits RTS on control channel, does not sense channel
• Node B receives RTS, sends CTS on control channel if it can
receive and does not know about ongoing transmissions
• B sends busy tone as it starts to receive data
Time
Control
channel
Data
channel
RTS
A ! B
CTS
B ! A
Data
A ! B
Busy tone
sent by B
22. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols22
PAMAS – Already ongoing transmission
• Suppose a node C in vicinity of A is already receiving a
packet when A initiates RTS
• Procedure
• A sends RTS to B
• C is sending busy tone (as it receives data)
• CTS and busy tone collide, A receives no CTS, does not send data
A
B
C
?
Time
Control
channel
Data
channel
RTS
A ! B
CTS
B ! A
No data!
Busy tone by C
Similarly: Ongoing
transmission near B
destroys RTS by
busy tone
23. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols23
Overview
• Principal options and difficulties
• Contention-based protocols
• Schedule-based protocols
• LEACH
• SMACS
• TRAMA
• IEEE 802.15.4
24. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols24
Low-Energy Adaptive Clustering Hierarchy (LEACH)
• Given: dense network of nodes, reporting to a central sink,
each node can reach sink directly
• Idea: Group nodes into “clusters”, controlled by
clusterhead
• Setup phase; details: later
• About 5% of nodes become clusterhead (depends on scenario)
• Role of clusterhead is rotated to share the burden
• Clusterheads advertise themselves, ordinary nodes join CH with
strongest signal
• Clusterheads organize
• CDMA code for all member transmissions
• TDMA schedule to be used within a cluster
• In steady state operation
• CHs collect & aggregate data from all cluster members
• Report aggregated data to sink using CDMA
25. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols25
LEACH rounds
26. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols26
SMACS
• Given: many radio channels, superframes of known length
(not necessarily in phase, but still time synchronization
required!)
• Goal: set up directional links between neighboring nodes
• Link: radio channel + time slot at both sender and receiver
• Free of collisions at receiver
• Channel picked randomly, slot is searched greedily until a
collision-free slot is found
• Receivers sleep and only wake up in their assigned time
slots, once per superframe
• In effect: a local construction of a schedule
27. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols27
SMACS link setup
• Case 1: Node X, Y both so far unconnected
• Node X sends invitation message
• Node Y answers, telling X that is
unconnected to any other node
• Node X tells Y to pick slot/frequency for the
link
• Node Y sends back the link specification
• Case 2: X has some neighbors, Y not
• Node X will construct link specification and
instruct Y to use it (since Y is unattached)
• Case 3: X no neighbors, Y has some
• Y picks link specification
• Case 4: both nodes already have links
• Nodes exchange their schedules and pick
free slots/frequencies in mutual agreement
Message exchanges
protected by
randomized backoff
28. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols28
TRAMA
• Nodes are synchronized
• Time divided into cycles, divided into
• Random access periods
• Scheduled access periods
• Nodes exchange neighborhood information
• Learning about their two-hop neighborhood
• Using neighborhood exchange protocol: In random access
period, send small, incremental neighborhood update information
in randomly selected time slots
• Nodes exchange schedules
• Using schedule exchange protocol
• Similar to neighborhood exchange
30. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols30
TRAMA – possible conflicts
• When does a node have to receive?
• Easy case: one-hop neighbor has won a time slot and announced
a packet for it
• But complications exist – compare example
• What does B
believe?
• A thinks it can send
• B knows that D has
higher priority in its
2-hop
neighborhood!
• Rules for resolving
such conflicts are
part of TRAMA
31. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols31
Comparison: TRAMA, S-MAC
• Comparison between TRAMA & S-MAC
• Energy savings in TRAMA depend on load situation
• Energy savings in S-MAC depend on duty cycle
• TRAMA (as typical for a TDMA scheme) has higher delay but
higher maximum throughput than contention-based S-MAC
• TRAMA disadvantage: substantial memory/CPU
requirements for schedule computation
32. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols32
Overview
• Principal options and difficulties
• Contention-based protocols
• Schedule-based protocols
• IEEE 802.15.4
33. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols33
IEEE 802.15.4
• IEEE standard for low-rate WPAN applications
• Goals: low-to-medium bit rates, moderate delays without
too stringent guarantee requirements, low energy
consumption
• Physical layer
• 20 kbps over 1 channel @ 868-868.6 MHz
• 40 kbps over 10 channels @ 905 – 928 MHz
• 250 kbps over 16 channels @ 2.4 GHz
• MAC protocol
• Single channel at any one time
• Combines contention-based and schedule-based schemes
• Asymmetric: nodes can assume different roles
34. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols34
IEEE 802.15.4 MAC overview
• Star networks: devices are associated with coordinators
• Forming a PAN, identified by a PAN identifier
• Coordinator
• Bookkeeping of devices, address assignment, generate beacons
• Talks to devices and peer coordinators
• Beacon-mode superframe structure
• GTS assigned to devices upon request
35. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols35
Wakeup radio MAC protocols
• Simplest scheme: Send a wakeup “burst”, waking up all
neighbors ! Significant overhearing
• Possible option: First send a short filter packet that includes the
actual destination address to allow nodes to power off quickly
• Not quite so simple scheme: Send a wakeup burst
including the receiver address
• Wakeup radio needs to support this option
• Additionally: Send information about a (randomly chosen)
data channel, CDMA code, … in the wakeup burst
• Various variations on these schemes in the literature,
various further problems
• One problem: 2-hop neighborhood on wakeup channel might be
different from 2-hop neighborhood on data channel
• Not trivial to guarantee unique addresses on both channels
36. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols36
Further protocols
• MAC protocols for ad hoc/sensor networks is one the most
active research fields
• Tons of additional protocols in the literature
• Examples: STEM, mediation device protocol, many CSMA variants
with different timing optimizations, protocols for multi-hop
reservations (QoS for MANET), protocols for multiple radio
channels, …
• Additional problems, e.g., reliable multicast
• This chapter has barely scratched the surface…
37. SS 05 Ad hoc & sensor networs - Ch 5: MAC protocols37
Summary
• Many different ideas exist for medium access control in
MANET/WSN
• Comparing their performance and suitability is difficult
• Especially: clearly identifying interdependencies between
MAC protocol and other layers/applications is difficult
• Which is the best MAC for which application?
• Nonetheless, certain “common use cases” exist
• IEEE 802.11 DCF for MANET
• IEEE 802.15.4 for some early “commerical” WSN variants
• B-MAC for WSN research not focusing on MAC